Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!milano!pp!nebula!ballou
From: ballou@nebula.ACA.MCC.COM (Nat Ballou)
Newsgroups: comp.object
Subject: Re: Inheritance is NOT Delagation (sic)
Message-ID: <351@nebula.ACA.MCC.COM>
Date: 13 Oct 89 14:01:34 GMT
References: <1989Oct13.020914.2811@brutus.cs.uiuc.edu>
Distribution: comp
Organization: MCC, Austin, TX
Lines: 17

From article <1989Oct13.020914.2811@brutus.cs.uiuc.edu>, 
by render@brutus.cs.uiuc.edu (Hal Render):
>>david@jpl-devvax.JPL.NASA.GOV (David E. Smyth) writes:

>>The average depth of inheritance in most systems is about 3. 
>>...

> I'm curious where you [found] that number.  I don't necessarily disbelieve 
> it, I just wonder where it came from, since I'd be surprised for large 
> systems written in class-oriented languages to have such a shallow tree.
> ...
> hal.

Don't believe it.  On the Lisp machine, the depth of the tree with root
SI:STREAM is at least 10 levels deep.  Also, I have seen object-oriented
databases with depths greater than 10.  I'm not familiar with SmallTalk, 
but I'd bet the class library is deeper than 3 in parts.  Any takers?